Respuesta :

the answer is 42x3 + 42x2
f(x) = 7x + 7; g(x) = 6x²

(fg)(x) = f(x) · g(x)

 (fg)(x) = (7x + 7)(6x²) = 7x · 6x² + 7 · 6x² = 42x³ + 42x²